Dental cream

ABSTRACT

Dental cream containing hydrated alumina, calcium carbonate or insoluble alkali metal metaphosphate as polishing agent, benzyl alcohol as desensitizing agent and zinc oxide. The cream does not swell or corrode unlined aluminum tubes when incorporated therein.

United States Patent [72] Inventors James Norfleet 506 Lee PL,Plainiield, NJ. 07063; Francis D. Roberts, 22 Crest Drive, W.Millington, NJ. 07946 [21] Appl. No. 818,047 [22] Filed Apr. 21, 1969[45] Patented Nov. 30, 1971 [54] DENTAL CREAM 9 Claims, No Drawings [52]US. Cl 424/57 [SI] Int.Cl A6lk 7/16 [50] Field of Search. 424/49-58 [56]References Cited UNITED STATES PATENTS 3,095,356 6/1963 Moss 424/513,227,618 1/1966 Manahan et al. 424/52 OTHER REFERENCES The Dispensatoryof the United States of America, 25th ed., published by J. B. LippincottCo., Phila., 1955, page 159 copy in Group 120 Primary ExaminerRichard L.Huff Attorneys-Herbert S. Sylvester, Murray M. Grill, Norman Blumenkopf,Ronald S. Cornell, Thomas .I. Corum, Richard N. Miller and Robert L.Stone ABSTRACT: Dental cream containing hydrated alumina, calciumcarbonate or insoluble alkali metal metaphosphate as polishing agent,benzyl alcohol as desensitizing agent and zinc oxide. The cream does notswell or corrode unlined aluminum tubes when incorporated therein.

DENTAL CREAM This invention relates to a dental cream composition. Moreparticularly it relates to a dental cream, having a desensitizing effecton the gums, which may be economically placed in unlined aluminum tubesfrom which it can be extruded without undesirable swelling or corrosionof the tube.

It has been desired to use unlined aluminum tubes for dental creamsparticularly in view of the economy in use of such tubes and theirlightweight. However, certain problems have been present when unlinedaluminum tubes have been used for dental creams in view ofnoncompatibility between the aluminum surface and components of dentalcreams. Thus, dental creams which contain a polishing material includinga major amount of at least one of hydrated alumina, calcium carbonateand insoluble alkali metal metaphosphate, and benzyl alcohol, an agentwhich has a mild-desensitizing effect on the gums may be difficult toextrude due to tube swelling or substantial undesirable corrosion (orcoloration) may occur at points of contact between the cream and thetube.

It is an object of this invention to provide a dental cream containing apolishing material including a major amount of at least one of hydratedalumina, calcium carbonate and insoluble alkali metal metaphosphate, andbenzyl alcohol which is storage stable upon incorporation in unlinedaluminum tubes and particularly does not cause substantial tube swellingor corrosion.

Other objects will be apparent from consideration of the followingdisclosure.

ln accordance with certain of its aspects, this invention relates to adental cream comprising about 20-75 percent by weight of awater-insoluble polishing material having as its major component atleast one of an agent selected from the group consisting of hydratedalumina, calcium carbonate and insoluble alkali metal metaphosphate,about 05-10 percent by weight of benzyl alcohol and about 0.l5-2 percentby weight of zinc oxide.

The instant composition normally has a pH between about 3.5 and 10 andpreferably on the order of about 6-9 and most preferably about 6.5.Suitably a bufi'ering system may be employed to assure maintenance of apH within the aforesaid range in order to insure against a reduction inactivity of the composition which occurs under more alkaline or acidicconditions.

The water-insoluble polishing material of the instant invention containsa major proportion (that is, at least 50 percent to 100 percent byweight of the polishing material) of hydrated alumina, calcium carbonateor insoluble alkali metal metaphosphate.

The hydrated alumina which may be employed in the instant invention isclassified as Gibbsite and may be represented chemically as Al O -3H orAl(OH) Its average particle size is about 6-9 microns. A typicalparticle size dis' tribution is as follows:

Less than 30 microns Less than 20 microns Less than 10 microns 56-67percent Less than microns 28-40 percent Other types of hydrated aluminamay also be used.

The calcium carbonate which may be used in the instant invention istypically employed in powder form of about 1 to microns. it is preferredto use a grade of calcium carbonate of apparent specific gravity, sayabout 0.7-1.2. Apparent specific gravity refers to the untamped specificgravity of the salt.

The insoluble alkali metal metaphosphates which may be used in theinstant invention are preferably the insoluble sodium and potassiumsalts of polymetaphosphoric acid. These materials are known in the art.The insoluble sodium metaphosphate is preferred. Such materials may beformed in any suitable manner, as illustrated by Thorpes Dictionary ofApplied Chemistry, vol. 9 (4th ed.), pp. 510-51 l. The forms ofinsoluble sodium metaphosphate known as Madrells salt and Kurrols saltare further examples of suitable materials.

94-99 percent 85-93 percent These metaphosphate salts exhibit only aminute solubility in water, and are commonly referred to as insolublemetaphosphates therefore. There is present a minor amount of solublephosphate material as impurities, usually of the order of a few percentsuch as up to about 4 percent by weight. The amount of soluble phosphatematerial which is believed to be a soluble sodium trimetaphosphate inthe case of insoluble sodium metaphosphate may be reduced by washingwith water if desired. The insoluble alkali metal metaphosphate istypically employed in powder form of a size such that no more than about1 percent of the material is larger than about 37 microns.

The polishing material may contain I00 percent of any of hydratedalumina, calcium carbonate or insoluble alkali metal metaphosphate orany of these agents in major amount in admixture with a minor amount ofone or both of the other agents or polishing agents such as dicalciumphosphate, tricalcium phosphate, calcium pyrophosphate, calcium sulfate,etc.

The polishing material content of the dental cream is variable, but willgenerally be about 20-75 percent by weight of the total composition.

The dental creams of the instant invention contain about 05-10 percentby weight, preferably about 075-315 percent, and most preferably about1.0-2.0 percent benzyl alcohol which has a desensitizing effect ontender areas and membranes in the oral cavity. The effect of benzylalcohol may be supplemented with about 0.3-3 percent by weight of thedental cream of Benzocaine, ethyl p-amino benzoate.

In the dental cream formulation, liquids and solids are proportioned toform a creamy mass of desired consistency. In accordance with certainaspects of this invention, the creamy mass is packaged in a collapsibleunlined aluminum tube.

in general, the liquids in the dental cream will comprise chiefly water,glycerine, aqueous solutions of sorbitol, propylene glycol, polyethyleneglycol 400, etc., including suitable mixtures thereof. It isadvantageous usually to use a mixture of both water and a humectant orbinder such as glycerine or sorbitol. The total liquid content willgenerally be about 20-75 percent by weight of the formulation. It ispreferred to use also a gelling agent in dental creams such as thenatural and synthetic gums and gumlike materials, e.g., Irish moss, gumtragacanth, sodium carboxymethyl cellulose, polyvinylpyrrolidone, starchand the like, usually in an amount up to about 10 percent, andpreferably about 0.2-5 percent of the formulation. When an astringent isemployed, the preferred gum is lrish moss.

Organic surface-active agents used in the compositions of the presentinvention may coact with the antimicrobial agent to achieve increasedprophylactic action, assist in achieving thorough and completedispersion of the instant compositions throughout the oral cavity, andrender the instant compositions more cosmetically acceptable. Theorganic surface active material may be anionic, nonionic, ampholytic, orcationic in nature, and it is preferred to employ as the surface activeagent a detersive material which imparts to the composition detersiveand foaming properties. Suitable such detergents are water-soluble saltsof higher fatty acid monoglyceride monosulfates, such as the sodium saltof the monsulfated monoglyceride of hydrogenated coconut oil fattyacids, higher alkyl sulfates, such as sodium lauryl sulfate, alkyl arylsulfonates, such as odium dodecyl benzene sulfonate, higher alkylsufcoacetates, higher fatty acid ester of 1,2 dihydroxy propanesulfonates, and the substantially saturated higher aliphatic acyl amidesof lower aliphatic amino carboxylic acid compounds, such as those havingl2 to 16 carbons in the fatty acid, alkyl or acyl radicals, and thelike. Examples of the last-mentioned amides are N-lauroyl sarcosine, andthe sodium, potassium, and ethanolamine salts of N-lauroyl, N- myristoylor N-palmitoyl sarcosinates, which should be substantially free fromsoap or similar higher fatty acid material which tends to substantiallyreduce the effect of these compounds. The use of these sarcosinatecompounds in dentifrice compositions of the present invention isparticularly advantageous since these materials exhibit a prolonged andmarked effect in the inhibition of acid in the oral cavity due tocarbohydrates, in addition to exerting some reduction 1.. the solubilityof tooth enamel in acid solutions.

Other suitable surface active materials include nonionic agents such ascondensates of sorbitan monostearate with approximately 60 moles ofethylene oxide, condensates of ethylene oxide with propylene oxidecondensates of propylene glycol (Pluronics") and cationic surface activegermicides and antibacterial compounds such as di-isobutylphenoxyethyldimethyl benzyl ammonium chloride, benzyl dimethyl stearyl ammoniumchloride, tertiary amines having one fatty alkyl group (of from l2 to 18carbon atoms) and two (poly)oxyethylene groups attached to the nitrogen(typically containing a total of from about 2 to 50 ethenoxy groups permolecule) and salts thereof with acids, and compounds of the structure(CHzCHzO) 1H (CHzCHgO);H

where R is a fatty alkyl group containing from about 12 to 18 carbonatoms, and x, y, and 2 total 3 or higher, as well as salts thereof withmineral or organic acids.

It is preferred to use from about 0.05 to percent by weight of theforegoing surface-active materials in the instant dental cream.

Various other materials may be incorporated in the dental creams of thisinvention. Examples thereof are coloring or whitening agents,preservatives, silicones, chlorophyll compounds, ammoniated materialssuch as urea, diammoniumphosphate and mixtures thereof, and otherconstituents. These adjuvants are incorporated in the instantcompositions in amounts which do not substantially adversely affect theproperties and characteristics suitably selected and used in properamount depending upon the particular type of preparation involved.

Antibacterial agents may also be employed in the dental creams of theinstant invention. Typical antibacterial agents includeN-(4-chlorobenzyl-N-"-(2,4-dichlorobenzyl) biguanide;

p-chlorophenyl biguanide;

4-chlorobenzhydryl biguanide;

4-chlorobenzhydrylguanylurea;

N-3-lauroxypropyl-N -p-chlorobenzylbiguanide;

l,6-di-p-chlorophenylbiguanidohexane;

l-( lauryldimethylammonium )-8-(p-chlorobenzyldimethylammonium) octanedichloride; 5,6-dichloro-2-guanidinobenzimidazole; N -p-chlorphenyl- N-laurylbiguanide; S-amino-l ,3-bis( 2-ethylhexyl)-5-methylhexahydropyrimidine; and their nontoxic acid addition salts.

The antibacterial agent, vwhen present, is employed in amounts of about0.01-5 percent by weight, preferably about 0.05-5 percent.

In accordance with this invention, it has been found that the presenceof zinc oxide permits dental creams containing benzyl alcohol in whichthe polishing material contains a major amount of any of hydratedalumina, calcium carbonate or insoluble alkali metal metaphosphate to beplaced in unlined aluminum tubes without substantial tube swelling orsubstantial tube corrosion occurring. The zinc oxide is present inamount of about 0.15-2 percent by weight of the total composition andpreferably about 0.5-1 percent.

When the polishing material contains a major amount of hydrated alumina,it is particularly desirable to also include an astringent, such as zincsulfate, zinc chloride, aluminum chloride and the like, in the cream.Typically, the astringent is present in amount of 025-3 percent, byweight, preferably 0.5-1 percent. The astringent may also be employedwith polishing materials other than hydrated alumina, such as calciumcarbonate.

Any suitable flavoring or sweetening sialagogue may be employed informulating the dental cream of the instant invention. Examples ofsuitable examples of flavoring constituents include flavoring oils suchas oils of spearmint, peppermint, clove, Wintergreen, Sassafras, sage,eucalyptus, marjoram, cinnamon, lemon and orange, as well as sodiumsalicylate. Suitable sweetening agents include sucrose, lactose,maltose, sorbitol, sodium cyclamate and saccharine. Suitably, the totalamount of sialagogue may comprise about 0.56 or more of the dental creamof the instant invention.

The compositions of the present invention suitably may also contain afluorine-containing compound having a beneficial efiect on the care andhygiene of the oral cavity, e.g., diminution of enamel solubility inacid and protection of the teeth against decay. Examples thereof includesodium fluoride, stannous fluoride, potassium fluoride, potassiumstannous fluoride (snF -KF), sodium hexafluorostannate, stannouschlorofluoride, sodium fluorozirconate, and sodium monofluorophosphate.These materials, which dissociate or release fluorine-containing ions inwater, suitably may be present in an effective but nontoxic amount,usually within the range of about 0.0] to 1 percent by weight of thewater soluble fluorine content thereof.

The following specific examples are further illustrative of the natureof the present invention but it is to be understood that the inventionis not limited thereto. All amounts and proportions are by weight unlessotherwise indicated.

The creams are prepared by adding zinc oxide (in creams A and B) to gelscontaining glycerine, Irish moss, sodium benzoate, sodium saccharine,water, zinc sulfate and sodium lauryl sulfate. The polishing material(hydrated alumina) is then added to form creams. Benzyl alcohol andflavor are next added.

The creams are placed in collapsible unlined aluminum tubes. Afterstorage at 49 C. for 6 weeks the tube in which cream C is present swellsand is corroded with a white layer. No such problems are present in thetubes containing creams A and B.

EXAMPLE 2 D E, parts parts Glyeerlne Irish moss Sodium carboxymethylcellulose Sodium benzoate Sodium saccharine" Water Sodium laurylsulfate. Zinc oxide. Polishing material:

Hydrated aluminazcalcium carbonate:1=9 52. 0 Calcium carbonate 52. 0Insoluble sodium metaphosphate 47.26 Hydrated almninazinsoluble sodiummetaphosphatezcalcium carbo- 1iate=1:7:39.25 Benzyl alcohol Flavor Thesedental creams are placed in unlined aluminum tubes. There is nosubstantial corrosion or tube swelling even after storage at 49 C. forseveral weeks. When zinc oxide is om ed from the above creams, uponstorage at 49 C., within 3 weeks, the tube containing the cream having1:9 ratio of hydrated alumina to calcium carbonate shows evidenceofcorrosion staining; the tube containing the cream having calciumcarbonate as the polishing material shows evidence of gold coloredcorrosion layer; the tube containing the cream having insoluble sodiummetaphosphate as the sole polishing agent shows evidence of the tubeswelling and formation of a black corrosion layer; and the tubecontaining the cream having the hydrated alumina, insoluble sodiummetaphosphate and calcium carbonate polishing material has black andgold colored corrosion stains.

It will be apparent to one skilled in the art that various modificationsmay be made and that equivalents can be substituted therefor.

We claim:

1. A dental cream comprising about -75 percent by weight of a dentallyacceptable water-insoluble polishing agent having hydrated alumina asits major component, about 0.5-5 percent by weight of benzyl alcohol andabout 0.15-2 percent by weight of zinc oxide.

2. The dental cream claimed in claim 1 wherein said zinc oxide ispresent in amount of about 0.5-1 percent.

3. The dental cream claimed in claim 1 wherein such benzyl alcohol ispresent in amount of about 0.75-3.5 percent.

4. A dental cream comprising about 20-52 percent by weight of a dentallyacceptable water-soluble polishing agent having calcium carbonate as itsmajor component, about 0.5-5 percent by weight of benzyl alcohol andabout 0.15-2 percent by weight of zinc oxide.

5. The dental cream claimed in claim 4 wherein said polishing materialis a mixture of a major amount of calcium carbonate and a minor amountof hydrated alumina.

6. The dental cream claimed in claim 4 wherein said polishing materialis a mixture of a major amount of calcium carbonate and minor amounts ofhydrated alumina and insoluble sodium metaphosphate.

7. The dental cream claim in claim 4 wherein said benzyl alcohol ispresent in amount of about 0.74-3.5 percent.

8. A packaged dental cream comprising an unlined aluminum tube havingincorporated therein a dental cream comprising about 20-75 percent byweight of a dentally acceptable water-insoluble polishing agent havinghydrated alumina as its major component, about 0.5-5 percent by weightof benzyl alcohol and about 0. l 5-2 percent by weight of zinc oxide.

9. A packaged dental cream comprising an unlined aluminum tube havingincorporated therein a dental cream comprising about 20-52 percent byweight of a dentally acceptable polishing agent having calcium carbonateas its major component, about 0.5-5 percent by weight of benzyl alcoholand about 0.15-2 percent by weight of zinc oxide.

2. The dental cream claimed in claim 1 wherein said zinc oxide ispresent in amount of about 0.5-1 percent.
 3. The dental cream claimed inclaim 1 wherein such benzyl alcohol is present in amount of about0.75-3.5 percent.
 4. A dental cream comprising about 20-52 percent byweight of a dentally acceptable water-soluble polishing agent havingcalcium carbonate as its major component, about 0.5-5 percent by weightof benzyl alcohol and about 0.15-2 percent by weight of zinc oxide. 5.The dental cream claimed in claim 4 wherein said polishing material is amixture of a major amount of calcium carbonate and a minor amount ofhydrated alumina.
 6. The dental cream claimed in claim 4 wherein saidpolishing material is a mixture of a major amount of calcium carbonateand minor amounts of hydrated alumina and insoluble sodiummetaphosphate.
 7. The dental cream claim in claim 4 wherein said benzylalcohol is present in amount of about 0.75-3.5 percent.
 8. A packageddental cream comprising an unlined aluminum tube having incorporatedtherein a dental cream comprising about 20-75 percent by weight of adentally acceptable water-insoluble polishing agent having hydratedalumina as its major component, about 0.5-5 percent by weight of benzylalcohol and about 0.15-2 percent by weight of zinc oxide.
 9. A packageddental cream comprising an unlined aluminum tube having incorporatedtherein a dental cream comprising about 20-52 percent by weight of adentally acceptable polishing agent having calcium carbonate as itsmajor component, about 0.5-5 percent by weight of benzyl alcohol andabout 0.15-2 percent by weight of zinc oxide.